1. Field of the Invention
The present invention relates to a solid-state image pickup device and a method for manufacturing a solid-state image pickup device.
2. Description of the Related Art
Solid-state image pickup devices including waveguides to increase the amount of light incident on photoelectric conversion units have recently been reported. Japanese Patent Laid-Open No. 2010-103458 discloses a method for embedding a high-refractive-index film in an opening in an insulating film in order to form a waveguide. Specifically, the method includes, at an early stage, forming a film under conditions in which a sputtering effect is high; and then forming a film under conditions in which a deposition effect is high.
Japanese Patent Laid-Open No. 2005-251804 discloses the inclination of side walls of waveguides to efficiently guide light to photoelectric conversion units. However, the inventors have found that the opening of the insulating film is likely to be clogged in forming a high-refractive-index member under conditions described in Japanese Patent Laid-Open No. 2010-103458 and that it is thus difficult to embed the high-refractive-index member without forming a void.
The inventors have found that the embedded high-refractive-index member is poorly bonded to a surrounding interlayer insulating film and thus can be detached therefrom and that an internal stress generated in the high-refractive-index member embedded can cause deformation of a wafer. Furthermore, the inventors have found that also in the structure described in Japanese Patent Laid-Open No. 2005-251804, it is difficult to embed a high-refractive-index member without forming a void when pixels are reduced in size.
According to aspects of the present invention, at least one of the foregoing problems is solved.